Art of coloring wood.



WILLIaM HALL, or roams. Y.

orrron;

ART OF COLORING WOOD.

To all .whom it may concern:

Be it known that I, \VILLIAM AUGUSTUS HALL,.8; citizen of the United States, residing at New York, in the county of New York and State of New York,'have invented or discovered certain new and useful Improvements in the Art of Coloring \Vood, of which the following is a specification.

This invention relates to the art of coloring wood so as to produce from some of the chem r or more common varieties of hard- W 00( such as birch, beech, or maple, close imitations of rarer or more QXPBIISIVG'WOOdS, such as mahogany or walnut; and the 1nvention has for its object to color the wood throughout to uniform shades, so that whencut up in making cabinet work, or for other purposes, there will bend-streaked or uncolored parts, and thejclosc imitations of more expensive-woods willtherefore be preserved. 1

r the heart wood as are weak structurally, but

-is not diffused or uniformly distributed throughout the denser parts ofthe wood. In almost every case wood thus treated, even for the longest time, and under the highest pressure practicable, will show totally 1m colored or very sli litly colored streaks or atchos which ran er the-same undesirable or commercial utilization. It has been discovered that this streaky effect can be over-,

come only by a difi'usion of the color'thr'ouglr out-the wood and that this can best be effected by aslow' cooking or boiling for a considerable time and at relatively low temperature. It is, however, impracticable to do this in the cylinders in which the wood .ias been treated, for the reason that the diffusion requires several days, and as the cylinder apparatus is very expensive it is not economical to utilize it for this purpose. Furthermore, the diffusion must be effected without any pressure and at a temperature not to exceed 212 F., so that the wood will not be injured by being subjected for a long time to high tem ratures.

. In practicing t e invention well-seasoned Specification of Letters Patent. Application tiled February 1, 1908. Serial No. 413,762.

exceed 212 F. This slow Patented Oct. 13, 1903 lumber is put into a cylinder or other suitable chamber and is then-preferably heated by indirect steam or otherwise to about 225 1*. A vacuum of about twenty-five inches is then ap ilied to withdraw the air from the cells of of the wood facilitating the removal of the air. After the air is completely removed a coloring solution, such as may be made from bark extracts or anhydrids of tannin, or from any suitable stains or dyes, is admitted to the chamber of the cylinder'and is forced into the wood,- under pressure. The pressure is maintained from'six or eight hours to fifteen or twenty hours, according to the hardness and thickness of-the wood, and the latter isthen removedfifrom the cylinder, and if examinedqinternally will'be found to present a streakyandartially colored appearance. The lumber is then preferably laced in o en vats in which it is? slowly bOl ad or coo red preferably in tliesame'solution with which it was treated in the cylinder, or in a similar solution, and for a ieriod of several days. If, however, the boiling bedone ina closed receptacle it should be" done at atmos )heric pressure, so that the temperature wi i not causes a general diffusion of the color in the wood'so that 'it will be of a uniform shade throughout Thick lumber is difiicult to color in an open vet, for the reason that the air in the oiling or cooking the wood, the previous heating cells in the central or inner parts of the wood acts as a repelling cushion, preventing proper circulation l, or penetration ,of the coloring solution, so' that, in such case, when the lumber is'removed from the coloring solution the wood has an uncolored innerportion or core.

vButi'by removing this air cushion by the vacu-- um process it becomes possible tocuusc the coloring solution to penetrate into the central parts of the wood, although this penetration is not uniform, and the coloring solution will be lodged largely in the ducts or pockets in the more porous rtions andconcentric rings, and it cannot e uniformly distributed throughout by any amount of pressure which may be applied. This uniform distribution or diffusion of the coloring mat ter which has thus been forced into the wood can, however, be effected by cooking or boiling the wood for a long time at relatively low temperatures and preferably n an open- 1:16

vat, as hereinbefore described {and this cooking or boiling in the coloring solution at rel ativel y' low temperatures is found to be more efiective fora uniform diffusion of the color ing material throughout the wood than a hard boiling at high temperatures and under high pressure, and also-avoids inuring the 'stren th of the lumber which is li ely to occur wrere the wood is subjected to high temperatures for any considerable length of time. 7 i Q Having thus described my invention or discover I claim and desire to secure by Letters fiatenti- 1., The herein-described rocess' for coloring wood, consisting in subjecting well-sasoned lumben to the action of a vacuum in a closed-chamber or receptacle, to draw the ai therefroqi andrender the same absorben then forcing a. coloring solution into.afid throughout the wood, so far as racticable,

by high pressure, and subsequent y diflusing the coloring matter in the wood by boiling orvcookin'g the latter for a long time in the coloring solution at a temperature not exceedin 212913.

2. T 'e herein-described process for coloring. wood, consistin in heatmg well-seasoned 'lumber in a close chamber or receptacle,

then subjecting the same to the action of a vacuum, to draw the air therefrom and ren .ing solution into and throughout tie wood,

der the wood absorbent, then forcin a colorso far as" practicable, b high pressure, and

' subsequently diffusing t 1e coloring matter in the wood by boiling or cooking the latter for a longtime in the-,coloring solution at a temperature not excaedin '21.2F. 3. The herein-descrl ed roces's for color ing wood, consisting in sn jecting well-sea sonedllnnber to the action of a vacuum inla closed chamber or receptacle, to draw the air therefrom and )render the same absorbent,

then forcing a coloring solution into and throu bout the wood, so far as racticable, by hig pressure, and subsequently diffusing the co orlng' matter in the wood by boiling or cooking the latter for a long time in the coloring solution in an open vat or receptacle.

4. The herein-described process for colorin'g wood, consistin in heating well-seasoned lumber in a close chamber or receptacle, then subjecting the same to the action of a vacuum, to draw the air therefrom and render the wood absorbent, then forcing 'a coloring solution into and throughout the wood, 1 so far as practicable, by hi h pressure, and subsequently diffusing the coormg matter in the wood by boiling or cooking the latter for a long time in the coloring solution in an open vat or receptacle.

In testimon whereof I affix my signature, in presence 0 two witnesses \VILLIAM AUGUSTUS HALL.

\Vitnesses:

ANNIE B. lVAL'rnns,

C. M. SWEENEY. 

